raworth



5 Sheets Sheet l.

J. S. RAWORTH.

(No Model.)

' STEAM ENGINE.

No. 584,704'. Patented June 15, 1897.

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(No Model.) 5 Sheets-Sheet 2.

- J. s. RAV/CMH STEAM ENGINE.

No. 584,704. Patsnted June 15,1897.

5 Sheets. Sheet 3.

(No Model.)

J. S. RAWORTH.. 4STMM ENGINE.

Patented June 15, 1897.

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5 Sheets Sheet 4.

(No Model.)

J. S. RAWQRTH. STEAM ENGINE.

Patented June 15,1897.

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5 Sheets-Sheet 5.

Patented June 15, 41897.

(No Model.) l

J. S. RAWO'RTI-I. STEAM ENGINIE.

Brien.

ATENT JOHN SMITH RAVORTH, OF LONDON, ENGLAND.

STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 584,704, dated J une 15, 1897.

Application tiled September 28,1895. Serial No. 563,374. (No model.) Patentedin Spain January 2, 1895,No. 18,152; in England March l, 1895, No. 4,442, and July 9, 1895, No. 24,751; in France July 9,1895, No. 248,768; in Belgium July 22, 1895, No. 116,655; in Germany August 111, 1895, No. 86,408; in Switzerland September 5,1895,No.l1,163;`in Hungary GtOliBI 27,1895, No. 4,023; in Austria November 30, 1895, No. 4,571; in New Zealand December 10, 1895, No. 8,197; in Victoria December 11, 1895, No. 12.732; Vin Queensland December l2, 1895, No. 8,207; in West Australia December 12, 1895, No. 787; in New South Wales December 14, 1895, No. 6,270, and in Italy December 31, 1895, LXXIX, 219.

To all 'wh/)771. zit mf/,Z/ coi/accru:

Be it known that I, JOHN SMITH RAwoRTH,

\ a subject of the Queen of Great Britain and Ireland, residing at Streatham, London, in the county of Surrey, England, have invented Improvements in Steam-Engines, of which the following is a specification, and for which patents have been granted in other countries as follows: Great Britain, No. 4,442, dated March 1, 1895, and No. 24,751, dated July 9, 1895; France, No. 248,768, dated July 9, 1895; Belgium, No. 116,655, dated July 22, 1895; Austria, No. 4,571, dated November 30, 1895; Hungary, No. 4,023, dated October 27, 1895; Germany, No. 86,408, dated August l1, 1895; Switzerland, No. 11,163, dated September 6, 1895; Spain, No. 18,152, dated January 2, 1895; Victoria, No. 12,732, dated December 11, 1895; Queensland, No. 8,207, dated December 12, 1895; New Zealand, No. 8,137, dated December 10, 1895; West Australia, No. 787, dated December 12, 1895; New South Wales, No. 6,270, dated December 14, 1895, and in Italy, Reg. Att.,Vol. LXXIX, No. 219, dated December 31, 1895.

My invention has reference to improvements in steam-engines in which two or more cylinders are used in tandem. According thereto the cylinders are placed one above the other or one in front of the other, according as the engine is vertical or horizontal, and the valves are placed between the adjacent ends of the cylinders-that is to say, in

compound engines the valves would be placed between the high-pressure and low-pressure cylinders, and in the case of a triple-expansion engine they would be placed between the adjacent ends of theseveral cylinders. By this means the clearances in the ports and passages are reduced to a minimum. I prefer to use valves of the well-known Corliss type, but similar results can be obtained with more or less efiiciency with other forms of valves.

Compound engines constructed in accordance with my invention are double-acting as regards the forces transmitted by the pistonrod, but are single-acting in each cylinder-- that is to say, the high-pressure steam acts upon the under side of the high-pressure piston and the expanded steam acts upon the upper side of the low-pressure piston in a vertical engine and upon the corresponding sides in a horizontal engine.

vIn the accompanying drawings, Figure 1 shows, partly in vertical section 011` the line A B of Fig. 2 and partly in elevation, a compound vertical steam engine constructed according` to this invention. Fig. 2 shows the engine in elevation, and Fig. 3 is a sectional View at right angles to Fig. 1. Figs. 4 and 5 are sections through the valve-box on the lines O D and E F, respectively, of Fig. 3, the valves and their driving mechanism being omitted. Figs. 6 to 10, inclusive,

are vertical sections illustrating cylinders and valve arrangements according to this invention for engines of various types.

Referring to Figs. 1, 2, and 3, the highpressure steam enters through the end of the valve-chamber d from the branch cl' and is admitted at suitable intervals by the valve g, vibrating on its axis, through the short direct port d to the high-pressure cylinder a, which is surrounded by a live-steam jacket When the high-pressure piston arrives at the top of its stroke, it passes a ring of port-holes a3, by means of which equilibrium is established between the steam-pressures in the cylinder a and the receiver Z, which is in communication by means of the ports Z Z with a chamber or pocket Z2, formed in a partition or valve-box arranged between the adjacent inner ends of the cylinders, and in which the valve-chambers d and e are also formed, Figs. 1, 3, 4, and 5. The high-pressure piston having now arrived, as described, at the top of its stroke and the high-pressure steam-port d havin g been previously closed,the low-pressure oscillating valve h will have commenced to open a passage through valve-chamber c and short direct ports e e2 between the highpressure cylinder a and the low-pressure cylinder b, and also to open passages through the said valve-chamber e and the ports Z3, e, and e2v between the receiver and the inner end of each cylinder, and each of these passages will remain open until the point of cut- `off is reached, say one-half to three-quarters of the stroke, when the passage c2 to the lowpressure cylinder will be closed and the steam remaining in the high-pressure cylinder will pass into the receiverZ ZZ through the ports Z3, Figs. lC and 5, which remain open to the highpressure cylinder until the valve h closes for compression. l

The low-pressure piston n on arriving at the bottom of its stroke passes a ring of portholes b, which allow the water and steam to pass out into the exhaust-chamber Zt, from which an outlet is provided at t. On the up or return stroke of the low-pressure piston n an outlet for the steam :remaining above the piston is provided through the pipe i by the exhaust-cavity of the valve 7L covering the two ports e2 e3.

The valves g and 77, are driven by levers iixed to the ends of their spindles, from eccentrics and rods, as shown in the drawings, or by any other well-known method suitable for the size and speed of the engine.

The method of governing shown in Figs. 2 and 3 is by means of a centrifugal governor carried by the crank-shaft and arranged to vary the throw of the eccentric used for driving the valve g, but an ordinary throttlevalve 'acting upon the steam-inlet may be used, if required.

During the downstroke of the high-pressure piston steam from the receiver Z obtains access to the top side of the piston m., In non-condensing engines this communication may be constant through holes in the cover CL4, but in condensing-engines it is bett-er to make it intermittent through the port-holes a3, as shown.

The steam-jacket ci is supplied with live steam through a small port d2, communicating with the valve-chamber CZ, and the condensed water is collected at each stroke in a` small pocket in the low-pressure valve Zt, being fed thereto by a similar port to a2, and by the motion of the valve carried round and discharged through a small port leading into the exhaust-cavity e5. rlhese ports and the corresponding pocket in the valve are merely drilled holes and are too small to be visible in the drawings. A relief-valve Z4 is placed in the head of the low-pressure cylinder to discharge water or excessive steam-pressure to the receiver Z Z2.

The cylinders are carried on a hollow truncated conical frame t, which for small engines may be cast in one piece,.but for large engines maybe built up in any convenient and suitable manner. This frame, which is provided with large openings for examination and repair of the engine, is closed in by a sheet-metal apron t', which retains the oil and returns it to the crank-chamber 0c, which forms part of the base-plate upon which the engine is built.

The crank-shaft bearings, which are of ordinary construction, are held down by wedgepieces o o and tightening-screws v2. The upper wedge-piece o slides in horizontal slots cut in the sides of the bearing-seat. The lubrication is effected by a small pump which draws oil from the crank-chamber and delivers it to the valvespindle bearings and joints at f, whence it descends by the hollow eccentric-rods to the eccentrics andby small pipes to the low-pressure gland s, and thence to the cross-head pin and guide.

Engines of various types, vertical, horizontal, or inclined, can be constructed with cylinders arranged in tandem with valves placed between them in the manner above set forth.

Figs. 6 to 1U, inclusive, are vertical sections illustrating the cylinder and valve arrangements of several constructions.

Fig. 6 shows parts of a simple engine having two single-acting high-pressure pistons m m', to the inner ends of which steam is alternately admitted from the valve-chamber CZ through short direct ports Z/ (Z2 by the cutoff valve g, the exhaust-valve 7i serving to place each cylinder in turn in communication Y-with the exhaust-pipe t' through the valve-chamber e. In this case the outer ends lof the cylinders ci a.' are closed, so that the same iiuid-for example, air-remains constantly therein, or they may have open ends communicating With the exhaust-pipe, as

shown on the right-hand side of Fig. 9. The valve-chambers are formed in a partition arg ranged between the inner ends of the cylinders", as in the arrangement shown in Figs. l 'to 5, inclusive, but' there is no receiver in this ease.

Fig. '7 shows parts of the arrangement represented in Figs'. l to 5, inclusive, and is j placed here in juxtaposition tothe others for the purpose of facilitating comparison.

y Fig. 8 shows parts of a compound engine' j consisting of two simple engines, of which the jleft hand one has two high-pressure pistons m m', as in Fig. 6, and exhausts into the righthand one, which linally exhausts into the pipe t, the two high-pressure cylinders `Ct ct being lsteam-jacketed and provided withreceivers `Z Z', like the cylinder ci in Fig. 7, andthe outer y ends of the two low-pressure cylinders b be'- ling in communication with the exhaust-piped, like the outer end of the cylinder?) in' Fig. 7. In this arrangement While high -pressure' steam' is being admitted into and is expandl ing in cylinder a, that Which has already done duty in cylinder a is permitted by the' valve h of the high-pressure engine to' pass partly jinto the valve-chamber CZ of the low-pressure engine and thence by valve g therein to the llow-pressure cylinder b and partly to the receiver Z of the cylinder a', the steam that has' already done duty in cylinder b escaping past the valve h of the low-pressure engine to the TOO IIO

staaf/e4E s exhaust t'. y Similarly when high-pressure steam is admitted to the cylinder a that which vhas done duty yin cylinder a passes partly to the receiver Z of that cylinder and partly to the cylinder b, while that in cylinder h' will be passing to the exhaust i. Y

Fig. 9 shows parts of a triple-expansion en gine composed of a compound engine con structed and operating like that shown in Figs. l to 5, inclusive, exhausting into a simple engine like that shown at the righthand side of Fig. 8. i Y

Fig. l shows parts of a quadruple-expansion engine consisting of two compound engines constructed and operating like that shown in Figs. l to inclusive, arranged in series, the several pistons being` of gradi'iallyincreasing size.

l. A compound steam-engine comprising high and low pressure cylinders arranged tandeinwise, an interposed partition, two independent Valve-chambers formed in said partition, the one being in communication with a steam-supply and the other with an exhaust, a short direct passage through said partition from the inner end of the high-pressure cyl inder to the valve-chamber connected with the steam-supply and a short direct passage from the inner end of each of said cylinders to the other valve'chamber and in each valvechamber a valve, said valves being independent of each other and adapted the one to admit high-pressure steam into the high-pressure cylinder at its inner end and the other to establish communication at the proper time between the high-pressure cylinder and the low-pressure cylinder and afterward between the low-pressure cylinder and the exhaust.

2. A compound steam-engine comprising high and low pressure cylinders arranged tandemwise, a receiver, communication between the receiver and the outer end of the high-pressure cylinder, a partition interposed between the two cylinders, a valve-chamber formed in said partition and which is in communication withthe supply of high-pressure steam and with the inner end of the high* pressure cylinder, a valve adapted to control said communication, a second valve'chamber also formed in said partition independently of the other and which has communications between it and t-he inner end of the highpressure cylinder, the inner end of the lowpressure cylinder, the receiver, and the exhaust, and an independent valve located in said lastmentioned valve-chamber and adapted to, at the proper time, place the inner end of the high pressure cylinder in communication with the low-pressure cylinder and for a time to place the inner ends of both these cylinders in communication with the receiver and subsequently to close the communication be tween the low-pressure cylinder and the receiver and to open communication between thelow-pressure cylinder and the exhaust. v

3. A steam-en gine comprising two cylinders arranged tandemwise, a partition arranged between the adjacent ends of said cylinders and formed with independent cylindrical valve-chambers having their axes at right angles to those of said cylinders and with short direct passages connecting the inner ends of said cylinders with said valve-chambers, independent oscillating cylindrical steam and exhaust valves located within said valveehambers and adapted to control the commu- Inication between the same and the adjacent with an exhaust,short direct passages through said partition from the inner end of each of said cylinders to each valve-chamber and a valve in each of said chambers, said valves being independent of each other and adapted the one to admit steam tothe inner end of each cylinder alternately and the other to place the inner end of each cylinder alternately in communication with the exhaust.

5, A steam-engine comprising two cylinders arranged tandemwise, a partition arranged between and transversely to the adjacent ends of said cylinders and formed with independent cylindrical steam and exhaust valve chambers having their axes at right anglesV to those of said cylinders, independent cylindrical cut-off and exhaust valves located in said chambers, short direct passages connecting eachvalve-chamber with the inner ends of the two cylinders, and a passage connecting the exhaust-valve chamber with an exhaustpipe, said passages being arranged to be controlled by the corresponding valves, substantially as described.

6. A compound single-acting steam-engine comprising a high-pressure cylinder, a lowpressure cylinder, a partition arranged between the adjacent ends of said cylinders and formed with separate cylindrical valve-charm bers one of which is connected with the inner end of the high-pressure cylinder and the other with the inner end of each eylin` der, an independent cylindrical valve adapted to control the passage of high-pressure steam from one valve-chamber to the inner end of the high-pressure cylinder, an independent cylindrical valve adapted to control the passage of steam from the inner end of the highpressure cylinder to the corresponding end of the low-pressure cylinder and from the latter cylinder to the exhaust, and means for oscillating said valves, substantially as herein described.

7. A compound single-acting engine comprising a high-pressure cylinder and a lows IOO IOS

IIO

pressure cylinder arranged tandemwise, a partition located between the adjacent ends of said cylinders and formed with two independent valve-chambers one of which communicates through a short direct port with the high-pressure cylinder and the other through short direct ports with both cylinders, independent cylindrical valves located within said chambers and arranged to control said ports and a receiver formed partly bya chamber in said partition and partly by a casing surrounding said high-pressure cylinder, said receiver being adapted to communicate with the outer end of the highpressure cylinder through holes in the wall thereof and with the inner end of each cylinder through ports controlled by one of said valves,` substantially as herein described for thel purpose specified.

8. A steam-engine comprising a high-presf vceive'r Z surrounding said high-pressure cylinderand communicating withl said pockets Z2 by ports Z', an exhaust-chamber Zr; into which sure cylinder ot having ports as in the outer end portion of its wall, a low-pressure cylinder b arranged in tandem with said cylinder ct and formed with exit-ports h near its outer end, connected pistons working in said cylinders, a partition arranged between said cylinders and formed with cylindrical valvechambers CZ and e, ports cZ, e, e2, e3 and b3,

eXhaust-cavit e5 and =ocketsb2 a receiver Z ',name to this specifica-tion in the presence of surrounding said high-pressure cylinder and in communication with said ports as and withsaid pockets, a cylindrical high pressure valve g controlling said port CZ, a cylindrical low-pressure valve h controlling said ports l e', e2, e3, and b3, means for oscillating each of said valves, and an exhaust-pipe communieating with said exhaust-cavity e5 andoports b', substantially as described for the purpose specified.

9. A single-acting compound steam-engine comprising a high-pressure cylinder a having a steam-jacket a', perforations a3, and piston m, a low-pressure cylinder b arranged tandemwise with regard to said cylinder a and provided with a row of perforations Z9',

and a piston n connected to said piston m j and to the crank-shaft of the engine, a valveboX located between the adjacent ends of said cylinders and provided with steamchambers d and c, pockets Z2 and steam-ports i d2, CZ', c', e2, e3, Z3, and e5, and a relief-valve Z4 and oscillatin 7i valve arranged in cham- 7 b CJ Tber d and adapted to control port` d', an oscillating valve h arranged in chamber e and adapted to control ports e', e2, e3, and Z3,

means for operating said Valves, a steam-rethe perforated lower or outer end of said cylinder b extends, and an exhaust-pipe 12in comi munication with said port c5 and chamber 16, all substantially as herein described for f the purpose specified.

In testimony whereof I have signed my two subscribing Witnesses.

JOHN SMITH RAWORTI-I.

Witnesses:

EDMUND S. SNEWI'N, WM. O. BROWN. 

